Valve-gear for steam-engines



2 Sheets-Sheet 1.

P. H. BALL. Valve Gear for Steam Engines. No. 229,797. Patented July 13,1880.

' 0 D B DA. E

ATTY

N-P'ETERS, PHO'IQUTHOGRAPHQL WASHINGTON. D C.

2' Sheets-Sheet 2. I. H. BALL. Valve Gear for Steam Engines. No.229,797. Patented July 13, I880.

NPEIERS. PNOTOLITHOGHAFHER. WASHINGTON, D. c,

STATES P PAT NT OFFICE.

R ANK .H.BALL, or ERIE, PENNSYLVANIA.

I T/ AL VE-GEAR FOR TEAM-lENGINES.

SPECIFIOATIONiforming partofLetters Fatent.i\l'o.l229,79"7, dated July13, 1880.

' Application filed December-4,1879.

' full, clear, and-exact description thereof.

My improvement in the valve-gear of a steam-engine consists in providingthe linkmovement of a reversible engine'with means whereby the saidengine may be made to run with more power in its forward than in itsreverse movement, or vice versa, and by which it can be adjusted at anytime so as to run with so; the adj'u.

more or less power in its forward movement or in its backward movementthan it formerly dld. In other words, my invention consists in providinga reversible steam-engine with means whereby it may be adjusted or setso as to most economically perform the work assigned it. The work to beperformed by a reversible steam-engineis often lightest when it isrunning reversed, and often the above conditions are reversed. Forexample, in running a hoist or crane, the forward work is much theheavier, while in running a saw-mill the reverse istrue; for although,when running reversed, as in gigging, the saw is not at work, the speedrequired to gig quickly requires that the steam be admitted to thecylinder throughout a greater part of the stroke of the piston than whenthe slow steady work of sawing is being done. So it is obvious that ifthe engine can be adjusted so as to more nearly consume the amount ofsteam required in each of its opera tions such a change will beeconomical.

Ofrcpurse, if it were known when the engine was being made what its workwas to be, the eccentrics of the valve-gear could' be then adjustedproperly; but such is not "always the case, and the same engine oftenchanges its work. So it is advantageous to havethe valvegear soconstructed as to be capable of proper adjustment. I effect this-by;mak'ing .one' of the eccentrics of the valve-gear adjustable, di-

rectly transverse the shaftyuponthe side of the other eccentric,which isfixed. By this means the throw of -;,one of the'ieccentri'cs can ha i etmentis directly transverse thesh'aft be r ie ..w t e1a b t th 21 1 thelead of the valve is not changed, but the cut-01f of the valve ischanged;

In setting up the engine the fixed eccentric can be made to cause thevalve to cut off, so as to have a reasonable amount of expansion ofsteam in the cylinder, and then the movable eccentric can be so adjustedas to run the engine with more or less expansion, as may be desired. Itwill therefore be preferable that the adjustable eccentric be the onethat moves the engine in its forward movement, as the engineer can thenadjust it so as to run with more or less expansion than the fixedeccentric provides for, and so adjust the engine to the character of thework it has to perform.

I am aware that it is not new to provide an eccentric with means wherebyit can be adj usted directly transverse the shaft.

My invention consists in combining within the valve-gear of a reversibleengine a fixed eccentric and a movable eccentric adjustable upon theside of the fixed eccentric, whereby the engine can be adjusted in themanner and for the purposes above set forth.

Figure 1 is a side elevation. Fig. 2 is an elevation taken on the rightof Fig. 1. Fig. 3 is a like view taken from the left'of Fig. 1. Fig. 4is a side elevation of a steam-engine valve-gear, and shows my inventionapplied tothe same.

A is the shaft, B the crank, and O D are the eccentrics, of thevalve-gear. R R are the connecting-rods, of whih R is attached to theeccentric which moves the engine in its forward movement, andR to theeccentric which moves the engine in the reverse movement. L is the link.P P are the pins on the valvestem with which the link engages. S is thevalve-stemguide, andV is the valve-chamber.

My device'is constructed as follows: The

' adjoining faces of the eecentricsare finished with a spline andgroove, 0 d; The eccentric G has its openingfor the shaft madeelliptical, as at a, Figs. 3 and'et. On one side of the eccentric D is aslot, e, in which is a set-screw, which screws into the other eccentric.

It will be seen that by means of the elliptical openinga in theeccentric G it can be moved laterally at right angles to the shaft,so'as to change its eccentricity, and by the set-screw Eit can besecured at any desirable point.

too

The spline and groove 0 d serve as a guide, and prevent any deviationfrom a direct rightangle movement of the eccentric in its adjustment.This is essential, as any deviation from a direct right-angle lateralmovement would change the lead of the valve, as we]! as its traverse orthrow, and would be fatal to the efiiciency of the device. Theadjustable eccentrio 0 is the one that moves the valve in the forwardmovement of the engine.

What I claim is as follows:

1. In the valve-gear of a reversible steam-englue, the combination, withthe reversing-link and connectingmods, of a fixed eccentric, with amovable eccentric attached to the side thereof I 5 slot e, and set-screwE, substantially as and 20 for the purposes set forth.

In testimony whereof I, the said FRANK H. BALL, have hereunto set myhand.

FRANK H. BALL.

Witnesses:

J No. K. HALLOCK, H. R. BARNHURST.

